CVE-2025-20352High· 7.7▾ Abyssal⚠ Exploited in the wildPoC availableA vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a denial of service …
▾ Abyssal zone — Critical with a public exploit or in-the-wild use
impact 42.4 · likelihood 7.9 · exploitation 25
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Public exploit / PoC code seen in 1 source. Availability, not in-the-wild use.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via CSAF
Federal remediation due Oct 20, 2025
Last analysed / modified upstream
39%
2 GitHub repos (last check)
Added to the CISA catalog on Sep 29, 2025. Federal remediation due Oct 20, 2025. View catalog ↗
A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following:
An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that is running Cisco IOS Software or Cisco IOS XE Software. To cause the DoS, the attacker must have the SNMPv2c or earlier read-only community string or valid SNMPv3 user credentials. An authenticated, remote attacker with high privileges could execute code as the root user on an affected device that is running Cisco IOS XE Software. To execute code as the root user, the attacker must have the SNMPv1 or v2c read-only community string or valid SNMPv3 user credentials and administrative or privilege 15 credentials on the affected device.
An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device over IPv4 or IPv6 networks.
This vulnerability is due to a stack overflow condition in the SNMP subsystem of the affected software. A successful exploit could allow a low-privileged attacker to cause the affected system to reload, resulting in a DoS condition, or allow a high-privileged attacker to execute arbitrary code as the root user and obtain full control of the affected system.
Note: This vulnerability affects all versions of SNMP.
Cisco has released software updates that addresses this vulnerability. There are no workarounds that address this vulnerability. There is a mitigation that addresses this vulnerability.
This advisory is part of the September 2025 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2025 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75296"].
Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability. Released 2025-09-24, updated 2025-10-06.
Affected:
Cisco has released software updates that address this vulnerability. https://software.cisco.com
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-76460Critical· 10.0A vulnerability in an API of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to bypass authentication. This vulnerability is due to insufficient authentication control on an API endpoint
CVE-2026-76461Critical· 9.8A vulnerability in the email parsing of Cisco AsyncOS Software for Cisco Secure Email Gateway could allow an unauthenticated, remote attacker to execute arbitrary commands with root privileges on the underlying operating system. This …
CVE-2026-20284Critical· 9.1A vulnerability in the SXP REST API of Cisco ISE could allow an authenticated, remote attacker to conduct SQL injection attacks. This vulnerability is due to insufficient validation of user-supplied input in REST API calls
CVE-2025-20151Medium· 4.3Cisco IOS and IOS XE Software SNMPv3 Configuration Restriction Vulnerability (CVE-2025-20151)
CVE-2026-20306Critical· 9.1A vulnerability in the REST API of Cisco ISE and ISE-PIC could allow an authenticated, remote attacker to perform command injection attacks on the underlying operating system and elevate privileges to root
CVE-2026-20305Critical· 9.1A vulnerability in the diagnostic tools of Cisco ISE and ISE-PIC could allow an authenticated, remote attacker to perform command injection attacks on the underlying operating system and elevate privileges to root